1. Solstice
Imaginary vertical line that cuts through the center of the Earth and around which Earth spins.

2. Earth’s yearlong orbit around the Sun
Axis
Earth’s yearlong orbit around the Sun

3. Revolution
For the Earth it is 23.5o. This is responsible for the different seasons

4. Tilt
Twice yearly time (spring and fall) when the Sun is directly over the Equator and daylight = night time

5. Equinox
Spinning of Earth on its imaginary asix, which takes about 24 hours. Causes night and day.

6. Rotation
Short period of climatic change in an area caused by the tilt of Earth’s axis.

7. Seasons
Change in appearance of the Moon as viewed from Earth, due to the relative positions of the Moon, Earth, and the Sun.

8. Moon Phase
Protons + Neutrons

9. Mass Number
Moon phases at which point the lighted side of the Moon can not be seen.

10. New Moon
Describes phases following a new moon as more of the Moon’s lighted side becomes visible.

11. A variable that remains the same during an experiment
Waxing
A variable that remains the same during an experiment

12. Constant
Occurs when the Moon passes directly between the Sun and Earth and casts a shadow over part of Earth.

13. The factor that changes in an experiment
Solar Eclipse
The factor that changes in an experiment

14. Occurs when Earth’s shadow falls on the Moon
Independent Variable
Occurs when Earth’s shadow falls on the Moon

15. Lunar Eclipse
Describes phases that occur after a full moon, as the visible lighted side of the Moon grows smaller.

16. Waning
Protons - Electrons

17. Charge
A resource in an ecosystem that prevents the population from growing larger.

18. Limiting Factor
The number of a species that an ecosystem can sustain with the resources it has available

19. Carrying Capacity
The variable that trying to be determined as a result of the experiment

20. Dependent Variable
Twice yearly point at which the Sun reaches its greatest distance north or south (longest and shortest day of the year)